<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */
defined('BASEPATH') or exit('No direct script access allowed');

/**
 * Database Result Class
 *
 * This is the platform-independent result class.
 * This class will not be called directly. Rather, the adapter
 * class for the specific database will extend and instantiate it.
 *
 * @category Database
 * @author EllisLab Dev Team
 * @link https://codeigniter.com/user_guide/database/
 */
class CI_DB_result
{

    /**
     * Connection ID
     *
     * @var resource|object
     */
    public $conn_id;

    /**
     * Result ID
     *
     * @var resource|object
     */
    public $result_id;

    /**
     * Result Array
     *
     * @var array[]
     */
    public $result_array = array();

    /**
     * Result Object
     *
     * @var object[]
     */
    public $result_object = array();

    /**
     * Custom Result Object
     *
     * @var object[]
     */
    public $custom_result_object = array();

    /**
     * Current Row index
     *
     * @var int
     */
    public $current_row = 0;

    /**
     * Number of rows
     *
     * @var int
     */
    public $num_rows;

    /**
     * Row data
     *
     * @var array
     */
    public $row_data;
    
    // --------------------------------------------------------------------
    
    /**
     * Constructor
     *
     * @param object $driver_object            
     * @return void
     */
    public function __construct(&$driver_object)
    {
        $this->conn_id = $driver_object->conn_id;
        $this->result_id = $driver_object->result_id;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Number of rows in the result set
     *
     * @return int
     */
    public function num_rows()
    {
        if (is_int($this->num_rows)) {
            return $this->num_rows;
        } elseif (count($this->result_array) > 0) {
            return $this->num_rows = count($this->result_array);
        } elseif (count($this->result_object) > 0) {
            return $this->num_rows = count($this->result_object);
        }
        
        return $this->num_rows = count($this->result_array());
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Query result.
     * Acts as a wrapper function for the following functions.
     *
     * @param string $type
     *            or a custom class name
     * @return array
     */
    public function result($type = 'object')
    {
        if ($type === 'array') {
            return $this->result_array();
        } elseif ($type === 'object') {
            return $this->result_object();
        } else {
            return $this->custom_result_object($type);
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Custom query result.
     *
     * @param string $class_name            
     * @return array
     */
    public function custom_result_object($class_name)
    {
        if (isset($this->custom_result_object[$class_name])) {
            return $this->custom_result_object[$class_name];
        } elseif (! $this->result_id or $this->num_rows === 0) {
            return array();
        }
        
        // Don't fetch the result set again if we already have it
        $_data = NULL;
        if (($c = count($this->result_array)) > 0) {
            $_data = 'result_array';
        } elseif (($c = count($this->result_object)) > 0) {
            $_data = 'result_object';
        }
        
        if ($_data !== NULL) {
            for ($i = 0; $i < $c; $i ++) {
                $this->custom_result_object[$class_name][$i] = new $class_name();
                
                foreach ($this->{$_data}[$i] as $key => $value) {
                    $this->custom_result_object[$class_name][$i]->$key = $value;
                }
            }
            
            return $this->custom_result_object[$class_name];
        }
        
        is_null($this->row_data) or $this->data_seek(0);
        $this->custom_result_object[$class_name] = array();
        
        while ($row = $this->_fetch_object($class_name)) {
            $this->custom_result_object[$class_name][] = $row;
        }
        
        return $this->custom_result_object[$class_name];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Query result.
     * "object" version.
     *
     * @return array
     */
    public function result_object()
    {
        if (count($this->result_object) > 0) {
            return $this->result_object;
        }
        
        // In the event that query caching is on, the result_id variable
        // will not be a valid resource so we'll simply return an empty
        // array.
        if (! $this->result_id or $this->num_rows === 0) {
            return array();
        }
        
        if (($c = count($this->result_array)) > 0) {
            for ($i = 0; $i < $c; $i ++) {
                $this->result_object[$i] = (object) $this->result_array[$i];
            }
            
            return $this->result_object;
        }
        
        is_null($this->row_data) or $this->data_seek(0);
        while ($row = $this->_fetch_object()) {
            $this->result_object[] = $row;
        }
        
        return $this->result_object;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Query result.
     * "array" version.
     *
     * @return array
     */
    public function result_array()
    {
        if (count($this->result_array) > 0) {
            return $this->result_array;
        }
        
        // In the event that query caching is on, the result_id variable
        // will not be a valid resource so we'll simply return an empty
        // array.
        if (! $this->result_id or $this->num_rows === 0) {
            return array();
        }
        
        if (($c = count($this->result_object)) > 0) {
            for ($i = 0; $i < $c; $i ++) {
                $this->result_array[$i] = (array) $this->result_object[$i];
            }
            
            return $this->result_array;
        }
        
        is_null($this->row_data) or $this->data_seek(0);
        while ($row = $this->_fetch_assoc()) {
            $this->result_array[] = $row;
        }
        
        return $this->result_array;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Row
     *
     * A wrapper method.
     *
     * @param mixed $n            
     * @param string $type
     *            'array'
     * @return mixed
     */
    public function row($n = 0, $type = 'object')
    {
        if (! is_numeric($n)) {
            // We cache the row data for subsequent uses
            is_array($this->row_data) or $this->row_data = $this->row_array(0);
            
            // array_key_exists() instead of isset() to allow for NULL values
            if (empty($this->row_data) or ! array_key_exists($n, $this->row_data)) {
                return NULL;
            }
            
            return $this->row_data[$n];
        }
        
        if ($type === 'object')
            return $this->row_object($n);
        elseif ($type === 'array')
            return $this->row_array($n);
        else
            return $this->custom_row_object($n, $type);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Assigns an item into a particular column slot
     *
     * @param mixed $key            
     * @param mixed $value            
     * @return void
     */
    public function set_row($key, $value = NULL)
    {
        // We cache the row data for subsequent uses
        if (! is_array($this->row_data)) {
            $this->row_data = $this->row_array(0);
        }
        
        if (is_array($key)) {
            foreach ($key as $k => $v) {
                $this->row_data[$k] = $v;
            }
            return;
        }
        
        if ($key !== '' && $value !== NULL) {
            $this->row_data[$key] = $value;
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns a single result row - custom object version
     *
     * @param int $n            
     * @param string $type            
     * @return object
     */
    public function custom_row_object($n, $type)
    {
        isset($this->custom_result_object[$type]) or $this->custom_result_object($type);
        
        if (count($this->custom_result_object[$type]) === 0) {
            return NULL;
        }
        
        if ($n !== $this->current_row && isset($this->custom_result_object[$type][$n])) {
            $this->current_row = $n;
        }
        
        return $this->custom_result_object[$type][$this->current_row];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns a single result row - object version
     *
     * @param int $n            
     * @return object
     */
    public function row_object($n = 0)
    {
        $result = $this->result_object();
        if (count($result) === 0) {
            return NULL;
        }
        
        if ($n !== $this->current_row && isset($result[$n])) {
            $this->current_row = $n;
        }
        
        return $result[$this->current_row];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns a single result row - array version
     *
     * @param int $n            
     * @return array
     */
    public function row_array($n = 0)
    {
        $result = $this->result_array();
        if (count($result) === 0) {
            return NULL;
        }
        
        if ($n !== $this->current_row && isset($result[$n])) {
            $this->current_row = $n;
        }
        
        return $result[$this->current_row];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns the "first" row
     *
     * @param string $type            
     * @return mixed
     */
    public function first_row($type = 'object')
    {
        $result = $this->result($type);
        return (count($result) === 0) ? NULL : $result[0];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns the "last" row
     *
     * @param string $type            
     * @return mixed
     */
    public function last_row($type = 'object')
    {
        $result = $this->result($type);
        return (count($result) === 0) ? NULL : $result[count($result) - 1];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns the "next" row
     *
     * @param string $type            
     * @return mixed
     */
    public function next_row($type = 'object')
    {
        $result = $this->result($type);
        if (count($result) === 0) {
            return NULL;
        }
        
        return isset($result[$this->current_row + 1]) ? $result[++ $this->current_row] : NULL;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns the "previous" row
     *
     * @param string $type            
     * @return mixed
     */
    public function previous_row($type = 'object')
    {
        $result = $this->result($type);
        if (count($result) === 0) {
            return NULL;
        }
        
        if (isset($result[$this->current_row - 1])) {
            -- $this->current_row;
        }
        return $result[$this->current_row];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns an unbuffered row and move pointer to next row
     *
     * @param string $type
     *            or a custom class name
     * @return mixed
     */
    public function unbuffered_row($type = 'object')
    {
        if ($type === 'array') {
            return $this->_fetch_assoc();
        } elseif ($type === 'object') {
            return $this->_fetch_object();
        }
        
        return $this->_fetch_object($type);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * The following methods are normally overloaded by the identically named
     * methods in the platform-specific driver -- except when query caching
     * is used.
     * When caching is enabled we do not load the other driver.
     * These functions are primarily here to prevent undefined function errors
     * when a cached result object is in use. They are not otherwise fully
     * operational due to the unavailability of the database resource IDs with
     * cached results.
     */
    
    // --------------------------------------------------------------------
    
    /**
     * Number of fields in the result set
     *
     * Overridden by driver result classes.
     *
     * @return int
     */
    public function num_fields()
    {
        return 0;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Fetch Field Names
     *
     * Generates an array of column names.
     *
     * Overridden by driver result classes.
     *
     * @return array
     */
    public function list_fields()
    {
        return array();
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Field data
     *
     * Generates an array of objects containing field meta-data.
     *
     * Overridden by driver result classes.
     *
     * @return array
     */
    public function field_data()
    {
        return array();
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Free the result
     *
     * Overridden by driver result classes.
     *
     * @return void
     */
    public function free_result()
    {
        $this->result_id = FALSE;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Data Seek
     *
     * Moves the internal pointer to the desired offset. We call
     * this internally before fetching results to make sure the
     * result set starts at zero.
     *
     * Overridden by driver result classes.
     *
     * @param int $n            
     * @return bool
     */
    public function data_seek($n = 0)
    {
        return FALSE;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Result - associative array
     *
     * Returns the result set as an array.
     *
     * Overridden by driver result classes.
     *
     * @return array
     */
    protected function _fetch_assoc()
    {
        return array();
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Result - object
     *
     * Returns the result set as an object.
     *
     * Overridden by driver result classes.
     *
     * @param string $class_name            
     * @return object
     */
    protected function _fetch_object($class_name = 'stdClass')
    {
        return new $class_name();
    }
}
